<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Test Simple Iframe</title>
</head>
<body>
    <h1 id="main-heading">Main Page</h1>
    <div id="main-content">
        <p id="main-paragraph">This is the main page content.</p>
        <button id="main-button">Main Button</button>
        <input id="main-input" type="text" placeholder="Main input">
    </div>
    
    <iframe id="simple-iframe" src="test_iframe_content.html" style="width: 800px; height: 600px;"></iframe>
    
    <div id="after-iframe">
        <p>Content after iframe</p>
    </div>
</body>
</html>

